1. Field of the Invention
The present invention pertains to systems and methods for testing printed circuit boards, and more particularly to a system and method for automatically comparing test points of a printed circuit board.
2. General Background
Generally, a Printed Circuit Board (PCB) is capable of printing a certain circuit on a substrate formed of a paper phenol or glass epoxy after coating a thin copper film thereon and removing the non-printed portion of the substrate based on an etching technique. Electrical parts such as IC are mounted on the surface of the substrate by a PCB welding method.
Recently, the PCB has become light and small-sized for mounting a highly integrated part thereon based on an advanced technique, and is a basic element for increasing the integrity of the electrical parts. Therefore, the importance of the same attracts a big attention. The pattern of the recently fabricated PCB becomes intensive based on the increased integrity, so that a more intensive pattern printing process is needed, and an error possibility is increased. It is recognized that a defect test of the PCB is important.
The defect test of the PCB is implemented by applying an electrical signal to a certain contact point of the PCB which is a tested object for thereby checking an electrical connection state of the contact point of the PCB. Namely, the test of the PCB is performed using a PCB test device. The PCB test device typically includes a test pin unit having a test pin capable of contacting a certain contact point of the PCB and applying an electrical signal to the contact point, and a test pin feeding device capable of feeding the test unit in a 2-axis direction with respect to the PCB. The test unit is fed to a certain place of the PCB based on a 2-axis direction movement using the feeding device and applies an electrical signal to a certain contact point which is judged to be tested using the test pin for thereby checking an electrical connection state, so that it is possible to check a defect state of the PCB.
Testing certain points of a PCB during the design course is much important, since most of possible errors can be avoided in this stage. Usually, there are various versions generated in different phases of designing the PCB. The machine structure and hardware frames of the versions are always the same, and the slight difference may exist in network traces, function modules, and locations of the test points. However, in the conventional methods for testing such PCBs, engineers need to adjust or reprogram the test devices, so test efficiency is very slow.
Therefore, what is needed is a system and method for automatically comparing test points of a PCB in different design versions, which can generate a comparison report according to comparison results in order that engineers can adjust slightly the test devices according to the comparison report.